Ubiquinone
Mostrando 25-36 de 237 artigos, teses e dissertações.
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25. Ubiquinone-mediated coupling of NADH dehydrogenase to active transport in membrane vesicles from Escherichia coli.
Addition of ubiquinone-1 to E. coli ML 308-225 membrane vesicles dramatically increases coupling between NADH oxidation and active transport such that initial rates and steady-state levels of lactose and amino-acid accumulation are comparable to those observed during D-lactate oxidation. Similar but less dramatic effects are observed with the quinone and suc
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26. Restoration by Ubiquinone of Azotobacter vinelandii Reduced Nicotinamide Adenine Dinucleotide Oxidase Activity
Extraction with pentane virtually abolished reduced nicotinamide adenine dinucleotide oxidase activity in small particles from Azotobacter vinelandii, but activity was largely restored by added ubiquinone.
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27. A Salmonella typhimurium mutant dependent upon carbamyl aspartate for resistance to 5-fluorouracil is specifically affected in ubiquinone biosynthesis.
The isolation and properties of a mutant dependent upon exogenous carbamyl aspartate for resistance to 5-fluorouracil are described. The mutant was deficient in the synthesis of ubiquinone and accumulated a quinone provisionally identified as the ubiquinone precursor 2-octaprenyl-3-methyl-6-methoxy-1,4-benzoquinone. The mutation resulted in an alteration in
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28. Ubiquinone synthetic pathway in flagellation of Salmonella typhimurium.
Flagellation of Salmonella typhimurium was found to require a functional pathway for ubiquinone synthesis as well as growth in the presence of aliphatic or aromatic carboxylic acids. Selection for constitutive flagellation eliminated the requirement for growth in the presence of added carboxylic acids.
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29. Identification and Characterization of aarF, a Locus Required for Production of Ubiquinone in Providencia stuartii and Escherichia coli and for Expression of 2′-N-Acetyltransferase in P. stuartii
Providencia stuartii contains a chromosomal 2′-N-acetyltransferase [AAC(2′)-Ia] involved in the O acetylation of peptidoglycan. The AAC(2′)-Ia enzyme is also capable of acetylating and inactivating certain aminoglycosides and confers high-level resistance to these antibiotics when overexpressed. We report the identification of a locus in P. stuartii, d
American Society for Microbiology.
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30. Reaction of the Escherichia coli quinol oxidase cytochrome bo3 with dioxygen: the role of a bound ubiquinone molecule.
We have studied the kinetics of the oxygen reaction of the fully reduced quinol oxidase, cytochrome bo3, using flow-flash and stopped flow techniques. This enzyme belongs to the heme-copper oxidase family but lacks the CuA center of the cytochrome c oxidases. Depending on the isolation procedure, the kinetics are found to be either nearly monophasic and very
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31. Biosynthesis of Ubiquinone in Escherichia coli K-12: Biochemical and Genetic Characterization of a Mutant Unable to Convert Chorismate into 4-Hydroxybenzoate
A mutant strain of Escherichia coli unable to carry out the first specific reaction of ubiquinone biosynthesis, that is the conversion of chorismate into 4-hydroxybenzoate, has been isolated. The gene concerned maps at about minute 79 on the E. coli chromosome and has been designated ubiC. This gene is probably the structural gene for chorismate lyase since
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32. Mechanism of the electron transfer catalyst DsbB from Escherichia coli
The membrane protein DsbB from Escherichia coli is essential for disulfide bond formation and catalyses the oxidation of the periplasmic dithiol oxidase DsbA by ubiquinone. DsbB contains two catalytic disulfide bonds, Cys41–Cys44 and Cys104–Cys130. We show that DsbB directly oxidizes one molar equivalent of DsbA in the absence of ubiquinone via disulfide
Oxford University Press.
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33. Anticancer action of cubé insecticide: Correlation for rotenoid constituents between inhibition of NADH:ubiquinone oxidoreductase and induced ornithine decarboxylase activities
Rotenone and rotenoid-containing botanicals, important insecticides and fish poisons, are reported to have anticancer activity in rats and mice. The toxic action of rotenone is attributed to inhibition of NADH:ubiquinone oxidoreductase activity and the purported cancer chemopreventive effect of deguelin analogs has been associated with inhibition of phorbol
The National Academy of Sciences.
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34. Application of ubiquinone systems and electrophoretic comparison of enzymes to identification of clinical isolates of Aspergillus fumigatus and several other species of Aspergillus.
The ubiquinone systems and electrophoretic comparison of enzymes were used to determine the relatedness among 64 isolates of seven Aspergillus spp. These were 31 clinical and 3 nonclinical isolates of Aspergillus fumigatus Fres., 2 isolates of A. nidulellus Samson & W. Gams, 8 isolates of A. terreus Thom, 4 isolates of A. flavus Link, 1 isolate of A. oryzae
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35. The ispB gene encoding octaprenyl diphosphate synthase is essential for growth of Escherichia coli.
The Escherichia coli ispB gene encoding octaprenyl diphosphate synthase is responsible for the synthesis of the side chain of isoprenoid quinones. We tried to construct an E. coli ispB-disrupted mutant but could not isolate the chromosomal ispB disrupted mutant unless the ispB gene or its homolog was supplied on a plasmid. The chromosomal ispB disruptants th
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36. Isoprenoid quinones of "Afipia" spp.
The isoprenoid quinone contents of seven strains of "Afipia felis," the type strains of "A. clevelandensis" and "A. broomeae," and reference strains of three unnamed "Afipia" genospecies were determined by reverse-phase high-performance liquid chromatography. The quinone profiles of all "Afipia" strains were essentially identical, with ubiquinone 10 as the m